I was sitting here at work and brainstorming on ways to make my Jeep better.

I thought of this:

I have an 87 2.5L in an MJ. It has TBI.

My 1.9L Escort has an OBDII Multiport w/ plenum FI system that has proven itself over many times in rallies.

I want to fabricate an intake manifold from a stock 1.9L Escort and use it on the FI 2.5L.

On the Escort, I have a 3.8L TB, a 4.0L MAF, Cold air intake and a Superchip. All of this will handle the displacment increase with no problem. The stock OBDII system can handle 200 horsepower easy. I can have the Superchip reprogrammed for this extra cubes if that ends up being a problem.

I think the ignition would be a simple splice of the input wires.

What does everyone think?

Tim

P.S. Thanks in advance
:flipoff2: :D :flipoff2: :D

I think if you're willing to tackle it, go for it...

Not much to tackle.

The manifold will take about 3 hour to fab.

Pretty much a bolt up after that.

I am just trying to see if there is something that I am forgeting.

Tim

start the project youll find out anything you forgot real quick...

I'd say GO FOR IT:beer:

Just remember this, doing conversions is like getting groceries, there will ALWAYS be something you forgot.:smokin:

Well, I was thinking about it.

The ignition system is going to be the kicker.

The OBD-II is a combo of a magnetic pickup on the Cam, an ignition module, and the computer.

Computer sees the the cam is at a certain spot and fires the correct cylinder.

The 2.5 TBI, I don't know much about. It has a distributer without points. So, some how I am going to have to make that primary signal tell the OBD-II computer where the cam is.

Any suggestions? I could just make a little magnetic pick up and weld it to the distributer shaft which would effectively make it like the OBD-II system. Then just shuffle the secondary wires until I had the firing order correct.

Oooh, just thought of something. The redline in the Escort is about 6500 rpm. The 2.5 is about 5750. Will the extra 750 or so rpms toast the engine? Of course I can keep the rpms down but sometime I get excited and put it on the floor. I don't exactly want to set the piston toss record. :D

One last thing is the fuel rail. I am not certain it will be long enough to match up to the head of the 2.5. Maybe just leave the OBD-II manifold alone and make a little sub manifold that goes between the head and the OBD-II manifold. That would make the intake runner longer and therefore create a few extra ft-lbs of torque.

This is really sounding like a great mod.

Thanks!

Tim

P.S. Cant leave without this.......:flipoff2: :D :flipoff2: :D

Why don't you just swap to '91 and newer 2.5L Jeep stuff?

It should be a list like intake, TB (4.0L works here too), distributor, flywheel or a custom crank sensor.

You might have to swap cams to keep from running too lean though you might be able to ajust for that with the MAP sensor. Also modern 2.5l can adjust their timing to some extent by the crank position sensor and knock detector.

The modern Jeep stuff works just fine and I just can't see justifing the headache of figuring it all out when the later OE stuff should be soo much easier.

hmmm maybe a harmonic balancer with the crank sensor might be the answer... i dont know though just an idea. might want to glance at the mopar fuel injection kit (the expensive one) that they put on the old 4.2's with the computer and such you have the same problem they have it sounds like.

just something to look at to give you some ideas. maybe a wild goose chace just trying to help

You could talk to Howell and see if they are any help.

Actually, the newer 2.5 MPI is what gave me the idea. But that would cost to get the running gear off a totalled vehicle.

The reason of doing the OBD-II swap is that I know that system. I have extra parts coming out of my ears and it is really easy to find them. I already know what works and what doesn't. At least on the escort. :D I also have all the factory diagnostic tools for that system. That intake system is good for torque and is very efficent. About %92 at the redline in the 1.9. Plus I love breaking stuff. :D

As for the lean running issue. Heated O2 sensor. 'nuff said.

Harmonic Balancer is an idea. But that would cost something. Where as I can cut a slice out of a stock escort cam (i have) and weld in onto the distributer shaft for nothing.

Thanks. Keep 'em coming.

Tim
:beer:

i've had the 2.5L in the YJ up to 7500 before... and i tend to shift at about 5 grand when i'm playin around... under load, not just revving, and it still runs like a gem. those 4 bangers are pretty stout.

chalk it up to teenage behavior. besides, 4 bangers are cheap, right?